Typically, a blister package is one packing method as a thermoplastic plastic film or sheet, and is a method performed in such a manner that a mold manufactured in accordance with a shape of a product desired to be packed is installed in a molder, a content or product is put in a swelled portion of a plastic film or sheet formed by pressure forming or vacuum forming, and then only a flat part (flange portion) of the molded film or sheet is heat-sealed or attached, which is widely used in packaging of food, daily necessities, goods, refined chemicals, cosmetics, and the like.
Meanwhile, a liquid, creamy, or waxy content such as food including various sauces, cosmetics, and the like may also be packed using the blister package, and the blister package applied to this may be configured in such a manner that an eluted side end portion of a container with an arbitrary shape is made of the same material as the container in the manufacturing process, an outlet in the form of a single pipe for discharging a content by opening an inside of the outlet, as necessary, is maintained to be communicated, and a multi-layered cover paper for sealing is attached in an opening and the flange of the container so that the opening of the container is covered and sealed while a soft portion of the container is formed of a flat flange.
However, as to the blister package having such a basic configuration, there are two structures such as the conventional structure for discharging the content in which a perforated line connected up to both ends of the flange is formed while laterally traversing a discharge portion of the molded plastic film or sheet and the discharge portion is cut by breaking the discharge portion with respect to the perforated line when discharging the content so that the opening is opened to withdraw the content, and a structure in which an adhesive portion enabling the cover paper attached to the flange of the container to be attached to the flange to perform a sealing function and a non-adhesive portion preventing the cover paper from being attached to the flange to separate the cover paper from the flange so as to facilitate grasping when separating and removing the adhesive portion and the cover paper from each other are provided while giving a perforated line so that a cut part of the adhesive portion penetrates the discharge portion in a straight line.
Meanwhile, an amount of the content received in the container may be all consumed in a disposable manner, but an amount to be used multiple times may be received in the container in most cases, and therefore there is a demand for a structure in which the opening is sealed after the use even after opening the discharge portion.
However, in an existing opening structure of such a discharge portion, the semicircular discharge portion is completely opened when tearing-off the cover paper contacting the discharge portion through the perforated line so that discharge of the content is smoothly performed but the opened opening cannot be selectively blocked, and therefore a separate plug or the like should be provided to block the opened opening. In addition, in the existing opening structure, when the opening is not sealed, external air or foreign substances may be introduced into the container through the opening and cause spoilage of the content such as discoloration or a bad flavor, or the content may be hardened and cause a great reduction in the service life and side effects, and therefore reliability of the quality may be reduced.
In addition, the content is highly likely to be leaked through the opened opening, a periphery of the discharge portion may be contaminated and defile the appearance of the container, and inconvenience such as having to stand the container up straight may be caused.
In order to solve the above-described problems, there has been known a structure for improving a sealing property of an opened outlet, which is disclosed in registration number 20-0316761 of earlier filing of the present applicant. In such a structure for improving the sealing property, when attaching a cover paper attached to a flange of a container to perform a sealing function on an adhesive portion so that a non-adhesive portion for separating the cover paper from the adhesive portion is provided, a discharging non-adhesive portion which has a predetermined area may be artificially provided while communicating with the discharge portion of the container within the adhesive portion of the cover paper, and at the same time a perforated line which is perpendicular to a longitudinal direction of the container and whose cut part penetrates the discharging non-adhesive portion in a straight line may be formed in the non-adhesive portion, so that an opening through which the content can be discharged may be provided on a flat flange. Thus, the discharging non-adhesive portion may be forcedly opened in accordance with pressing and releasing of the container to discharge the content, or may be tightly pulled to its original state to maintain a plane while being brought into close contact on the flange so that the opening may be automatically closed, thereby improving sealing properties of the content.
However, in the above-described invention of the earlier filing of the present applicant, there is room for improvement due to the following problems.
First, the outlet opened by tearing-off the non-adhesive portion separated from the flange in order to withdraw the content may be sealed by tightly pulling the discharging non-adhesive portion by an elastic return force of the container itself after withdrawing a desired amount of the content. However, residues of the discharged content are coated around an entrance of the outlet as is and exposed to the outside, which defiles the appearance of the container, and the exposed content is highly likely to be hardened and acidified, and therefore inconvenience such as having to remove the content near the entrance one by one when using the container later may be caused, and the exposed and contaminated content may be unsanitary because it is highly likely to contaminate the remaining entire contents of the inside of the container.
Second, the entrance of the outlet which is sealed only through an elastic return force may be slightly opened because the outlet is difficult to completely and tightly seal due to the residual content near the entrance of the outlet, and therefore it is difficult to prevent the content from being leaked when a separate external force is applied to the container such as movement or possession of the container. As a result, there is an urgent demand for a reinforced sealing structure for additionally sealing the outlet.